NEW SITE ----> Go to http://www.miketnelson.com < -----for all my latest info a this site below is from about 5-8 years ago. Michael T Nelson, MS CSCS, RKC is a PhD
Candidate in Kinesiology (Exercise Physiology) at the U of MN and Fitness Consultant in White Bear Lake, MN. Ramblings here about research, training, nutrition, exercise phys, Z Health, joint mobility, and whatever else I want

Thursday, May 14, 2009

Performance Research for May: Protein Synthesis: Leucine and Layne Norton

Greetings! Some very cool studies below for yas and I apologize that I don't have time to add my comments per normal, but if there are any questions post them in the comments and I will get back to you as soon as I can.

Jodie and I are headed out super early tomorrow AM for Ryan Lee's Ozworth conference on business stuff for 3 days. It should be very interesting and I am looking forward to learning as much as I can so I can better help all of you! If you are there, please come up and say hi! If I miss you, email me at my normal address with the title URGENT and my assistant will call me with your contact information.

If you have sent an email, I will get back to you soon, but it probably won't be until next week. I know I probably said that last week too, but I will get back to you at some point.

The first study I need to send a huge congrats out to Layne Norton for getting it published! If you have not checked out his website, click on it below.Biolayne(for some reason my computer spits at me about the link, but it worked earlier today)

I know first hand how much effort goes into publishing studies! You can listen to Layne himself and a great discussion about protein on Super Human Radio below. Excellent info and interview

3 Division of Nutritional Sciences, Department of Food Science and Human Nutrition 4 Department of Animal Sciences University of Illinois at Urbana-Champaign, Urbana, IL 61801 5 Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Evansville, IN 47712

This study examined the impact of leucine (Leu) derived from complete meals on stimulation of skeletal muscle protein synthesis (MPS). Expt. 1 examined time course changes in translation initiation and MPS after a meal. Male rats (~300 g) were trained for 5 d to eat 3 meals/d providing 20, 50, and 30% of energy from whey protein, carbohydrates, and fats, respectively. Plasma and skeletal muscle were collected at time 0 (baseline) after 12 h of food deprivation and then at 45, 90, 135, 180, and 300 min after a 4-g meal.

Plasma Leu increased at 45 min and remained elevated through 180 min. MPS peaked at 45–90 min and returned to baseline by 180 min.

Leucine is known to stimulate muscle protein synthesis and anabolism. However, evidence for the efficacy of additional leucine to enhance the response of muscle anabolism to resistance exercise and protein ingestion is unclear. Thus, we investigated the response of net muscle protein balance to ingestion of additional leucine with protein in association with resistance exercise. Two groups of untrained subjects performed an intense bout of leg resistance exercise following ingestion of 1 of 2 drinks: flavored water (PL); or 16.6 g of whey protein + 3.4 g of leucine (W+L). Arteriovenous amino acid balance across the leg was measured to assess the anabolic response of muscle in each group.

Arterial amino acid concentrations increased in response to ingestion of W+L. Amino acid concentrations peaked between 60 and 120 min after ingestion, and then declined to baseline values. Valine concentration decreased to levels significantly lower than baseline. Net balance of leucine, threonine, and phenylalanine did not change following PL ingestion, but increased and remained elevated above baseline for 90-120 min following W+L ingestion. Leucine (138 +/- 37 and -23 +/- 23 mg), phenylalanine (58 +/- 28 and -38 +/- 14 mg), and threonine (138 +/- 37 and -23 +/- 23 mg) uptake was greater for W+L than for PL over the 5.5 h following drink ingestion.

CONCLUSION: Our results indicate that the whey protein plus leucine in healthy young volunteers results in an anabolic response in muscle that is not greater than the previously reported response to whey protein alone.

My notes: Ok, I could not resist. Looks like if you are using protein high in BCAAs and leucine, that EXTRA leucine may not be beneficiail (although does not appear to be harmful, unless you count money going out of your wallet as harmful)

In this review we discuss current findings in the human skeletal muscle literature describing the acute influence of nutrients (leucine-enriched essential amino acids in particular) and resistance exercise on muscle protein synthesis and mammalian target of rapamycin complex 1 (mTORC1) signaling. We show that essential amino acids and an acute bout of resistance exercise independently stimulate human skeletal muscle protein synthesis.

It also appears that ingestion of essential amino acids following resistance exercise leads to an even larger increase in the rate of muscle protein synthesis compared with the independent effects of nutrients or muscle contraction. Until recently the cellular mechanisms responsible for controlling the rate of muscle protein synthesis in humans were unknown. In this review, we highlight new studies in humans that have clearly shown the mTORC1 signaling pathway is playing an important regulatory role in controlling muscle protein synthesis in response to nutrients and/or muscle contraction.

CONCLUSION: We propose that essential amino acid ingestion shortly following a bout of resistance exercise is beneficial in promoting skeletal muscle growth and may be useful in counteracting muscle wasting in a variety of conditions such as aging, cancer cachexia, physical inactivity, and perhaps during rehabilitation following trauma or surgery.